A police detective goes undercover in this series, but he becomes a fifth-grade teacher, replacing the role left when the previous fifth-grade teacher was murdered. Now he is set to investigate what happened.

However, the plot is pretty fun and interesting. Toyama comes into the classroom and finds fifth-graders with some interesting quirks. But one in particular is Makoto, who is shunned by his classmates and left alone in social circles. He’s a target for the other kids’ mockery, and he takes it and doesn’t engage back with any of the other students.

Toyama ponders whether the bullying of Makoto could have a connection to the murder case, and he begins to investigate. When he begins to investigate, he finds out that the young boy Makoto has previously said he could see visions of monsters. Eventually, Toyama comes to understand Makoto a little bit better, and the two of them form an alliance of sorts to help sort out the mysteries of the murdered teacher.

Despite that set-up, there are quite some hiccups. For one, Toyama, the detective, is quite the chatterbox when it comes to him secretly working for the police. In addition, his actions sometimes bring attention to the fact that he is a detective, even though he is working undercover. It’s a bit difficult to take the character as a true figure when he makes such elementary mistakes.

In addition, the volume is rated for teens plus, although it feels a bit of a stretch for that age category. Given the eccentricities of the characters and how they make almost elementary mistakes, it appears as though a better age grouping for this would be for 10- to 14-year-olds. And the simplicity of the art style also adds a bit of a younger feel to this volume than the rating implies.

To top it off, the volume is quite short, coming in at around 150 pages of story.

Deka Kyoshi certainly has a few cracks in it, but if a preteen audience would read it, it would probably be a much better fit.